/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_AbortSignal_h
#define mozilla_dom_AbortSignal_h

#include "mozilla/dom/AbortFollower.h"
#include "mozilla/DOMEventTargetHelper.h"

namespace mozilla {
namespace dom {

// AbortSignal the spec concept includes the concept of a child signal
// "following" a parent signal -- internally, adding abort steps to the parent
// signal that will then signal abort on the child signal -- to propagate
// signaling abort from one signal to another.  See
// <https://dom.spec.whatwg.org/#abortsignal-follow>.
//
// This requires that AbortSignal also inherit from AbortFollower.
//
// This ability to follow isn't directly exposed in the DOM; as of this writing
// it appears only to be used internally in the Fetch API.  It might be a good
// idea to split AbortSignal into an implementation that can follow, and an
// implementation that can't, to provide this complexity only when it's needed.
class AbortSignal final : public DOMEventTargetHelper,
                          public AbortSignalImpl,
                          public AbortFollower {
 public:
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AbortSignal, DOMEventTargetHelper)

  AbortSignal(nsIGlobalObject* aGlobalObject, bool aAborted);

  JSObject* WrapObject(JSContext* aCx,
                       JS::Handle<JSObject*> aGivenProto) override;

  IMPL_EVENT_HANDLER(abort);

  static already_AddRefed<AbortSignal> Abort(GlobalObject& aGlobal);

  // AbortSignalImpl
  void SignalAbort() override;

  // AbortFollower
  void RunAbortAlgorithm() override { SignalAbort(); }

 private:
  ~AbortSignal() = default;
};

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_AbortSignal_h